Hi
Does bacteria exist in sub-absolute zero temperatures? I have looked but have found no websites with any mention of it.
I look forward to your feedback
Absolute zero means you can’t go any lower.
Absolute zero is the coldest temperature that can ever be, characterized by the complete absence of all molecular and atomic motion. So, no, there are no bacteria that exist in sub-absolute zero temperatures because nothing can be colder than absolute zero.
Maybe you are thinking of some other temperature? Below freezing, perhaps?
ETA: double-ninja’d. Shoulda refreshed.
There is no such thing as sub-absolute zero temperatures. That’s a meaningless concept.
Give us some more context on what you think you read and perhaps we can tease out the rest of what you’re looking for.
The actual sub-zero temperatures in those references was in a tiny quantity of atoms, in an artificial and precisely controlled laser trap apparatus. There’s certainly no bacteria in the cloud of laser-trapped atoms. If there is any on the inside of the apparatus, it’ll be above absolute zero. But I’d hazard a guess that this sort of equipment is cleaned thoroughly enough to be sterile.
Thanks lazybratsche. I had seen this wikipedia article(see below) and thought perhaps given the info on new research on sub-absolute zero temperatures that there were some possibility of bacteria at those temperatures (below absolute zero, -273.15˚C.)
“Tardigrades are notable for being the most resilient animal: they can survive extreme conditions that would be rapidly fatal to nearly all other known life forms. They can withstand temperature ranges from 1 K (−458 °F; −272 °C) (close to absolute zero) to about 420 K (300 °F; 150 °C),[7] pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space.[8] They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce.[3][9][10][11]”
What precisely is meant by “sub-absolute-zero” in those articles is a very subtle technical point, but suffice to say that they don’t mean the same thing by “temperature” that laymen do.
I’m no scientist, but from what I understand of the behavior of the atoms described in the SciAm article, a theoretical bacterium subjected to the same conditions couldn’t survive. Seems as though if it were even possible the thing would be torn apart as its component atoms reconfigure themselves.
Thank you Chronos. Can you perhaps explain the misunderstanding laymen have on this point?
I found the above as a starting point, but I’m hoping Chronos can give us some better intuition. It seems to rest on the technical thermodynamic definition of temperature that’s based on entropy.
ETA: there’s a Wiki too
The concept of absolute zero/sub-absolute zero seems to be a theoretical value only, not a physically achievable one. So I guess I misunderstood that point. Would that be correct?
There are certainly interesting related questions, though. A good definition of “life” is a machine to harness energy flow in order to maintain low entropy.
[QUOTE=Boltzmann]
The general struggle for existence of animate beings is not a struggle for raw materials – these, for organisms, are air, water and soil, all abundantly available – nor for energy which exists in plenty in any body in the form of heat, but a struggle for [negative] entropy, which becomes available through the transition of energy from the hot sun to the cold earth.
[/QUOTE]
I wouldn’t actually say that lay folks have a misconception about temperature. Rather, there’s a concept called “temperature” which is familiar to lay people, and which is a perfectly valid and useful concept. Under this concept, there is in fact a lowest possible temperature, which can never actually be reached but only approached, and this concept of temperature is applicable to questions like asking whether an organism can survive in an environment at that temperature.
But then physicists started noticing that there are other phenomena which are not exactly the same thing as classical “temperature” (for one thing, some of these other phenomena are allowed to have negative or even infinite values), but which are very closely analogous to it in a wide variety of ways. They’re so closely analogous, in fact, that it makes sense to call them by the same name. But they still occur in different contexts, sufficiently different that one can’t (for example) speak of bacteria or tardigrades being in such an environment.
It’s sort of like the distinction between hardware and software: One can speak of software having a “bug” in it, but it is not the same kind of bug that Grace Hopper found short-circuiting a relay. A literal fleshy moth cannot live inside a computer program. It’s not that the program is an inhospitable environment; it’s that it’s the wrong context entirely.
Great link. Thank you. I hadn’t read about this stuff before. That page set me off on a nice dozen-page Wikigrination. I love a day when I learn totally new stuff. If only I could remember more of the details tomorrow.
For an interesting discussion of negative absolute temperatures, Sixty Symbols has a good video:
This may be part of the confusion. I can’t believe that any lifeform could survive at a temperature that liquefies helium. I know there is a footnote to a Wired article, but since I have a long-standing suspicion that everything Wired publishes is wrong, I tried to confirm that temperature.
I couldn’t. Smithsonian magazine says this:
A link in that quote goes to Survival of Tardigrades in Extreme Environments: A Model Animal for Astrobiology. The abstract gives no numbers, unfortunately, but it’s a true scientific article. Other sites also cite that temperature, which is -200 °C, hugely warmer than absolute zero.
Actually, that I can believe. There are two main dangers to an organism from cold temperatures: That once the metabolic processes stop, they won’t start up again, and that ice crystals forming when they freeze will burst cells. By -200 C, you’re already well past both of those problems, and if the organism has survived to that point, it’s hard to see what harm any lower temperature could do.
As for why they didn’t test lower temperatures, I note that -200 C is (rounded) the boiling point of nitrogen, and hence a temperature easily and cheaply achieved by a lab even with no cryo equipment, but anything colder requires something more exotic. So the simplest possibility is that they did the coldest test they could easily do, and didn’t have enough interest in pushing the limits to test anything colder.
Fascinating stuff! Thanks Riemann.